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Discussion Starter · #1 ·
Alright I'm finalyl getting things underway with this car but I have a few more problems/questions.

I was having a problem keeping it running, on checking a third time I found a rather large slit in one of my couplers, so yea now it idles.

I fixed the bucking problem with the addition of the 4-wire tps, car is much smoother now.

So I've never really driven a turbo car other than this one, comparing to videos and how some of you talk about the gtx I must have something wrong with mine. It really doesnt feel that much more powerfull over stock, I mean it is more but not that much, like it wont "break the tires loose" easily and such.

I finally got a boost guage hooked up and the car didnt seem to be boosting past 5psi according to the guage. At Idle, the vacum is around 24 in hg. I'm going to have to triple check the line but I dont think I've kinked it at all. I'm thinking its accurate and thats why the car doesnt feel that much better. Is it possible the stock wastegate actuator is opening too early?

Another thing is timing, I know that without the knock controller you have to set it at 12degrees, but heres the thing, when I jumper ground and 10, the idle doesnt change, infact I dont see or hear anything to indicate the car going into diagnostic mode. Is this normal with the gtx ecu? Is there another place I can jumper other then at that terminal? I originally set it to 10 degrees before turboing so I've advanced the distribute a tiny bit.

It would probably help if I listed what I have...
1994 egt 5speed, bp05 block/head, gtx intake/exhaust mani, vj20, gtx360cc injectors, gtx ecu(rewired for tps&rpmcut), bp05 vaf, 4-wiretps, icpipe= 2" coldside, 2.5"hotside w/fmic & ssqv bov.

I also purchased a air/fuel guage but I'm thinking my o2 sensor is dead as the guage does nothing.

Any ideas would be great, thanks.
 

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Discussion Starter · #2 ·
I forgot to mention I have stock exhaust with a new(stock) cat, so probably somewhat restrictive.

I also installed a manual boost controller in the past hour, the guage now registers a max of 8psi and it definatly feels a little quicker by that point but it doesnt kick in until late. I'm at 5psi by 3k then 8 by 4500.

I'm not sure if that helps any, I'm thinking maybe the exhaust is preventing it from spooling quicker?
 

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With the factory exhaust you should feel the low end but will definitely start choking in the higher rpms, as no top end what so ever and really feel power drop in higher RPMs. Just the nature of turbo cars. They really hate small exhausts.
As for boost, dose it hit 8psi at all before dropping to 5psi, or dose it hit 5psi and the just hold there? Before boost controller of course. Is the ssqv a real or knock off?
VAF might need to be adjusted, but I can not confirm that right now.
What plugs and what are they gaped at?
 

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per the GTR book at stock boost they should be gapped at 38 running 63 or 7e plugs, I have never run the stock boost, the more you turn it up the closer the gap all the way down to .026-.028

check for vac leaks as the is a really high vac at idle for the BP should be 18-20 at 8-900 RPM

if you have a boost leak anywhere will also cause this problem, turn up the boost a bit say 12 psi (running GTX ECU) and watch the gauge then. Also where do you have the MBC and the Line hooked up for your gauge?

What VAM/VAF are you running? Wideband?

exhaust leaks? wastegate stuck open?

just some other things to look at.

-Steve
 

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Discussion Starter · #6 ·
I confirmed today the car is a dog lol I gave it everything it has and my friend in a 2.2 cavalier kept up no problem. Wastegate stuck open I'll check, it wasnt when it was off the car but I'll check now. I have the boost guage teed off the back of the intake mani on the vac line for gas tank purge. The wastegate line is connected directly to my charge pipe closest to the throttlebody, maybe 10 inches away from the flapper.

I'm running the stock egt vam but havnt tried adjusting it, and no unfortunatly I'm reaching an end of my funding and the beginning of college so no wideband. Narrownband with a dead o2.

There were exhaust leaks as I had a problem with stock gtx downpipe but they've been fixed.

Is there a good way to find a boost leak? I work with pvc products and was thinking of making a 2"barbed to air hose adapter to install at the turbo inlet coupling and connect it to a compressor w/guage to check. Was going to fill to maybe 15psi and see if it holds, is this a safe way of doing it?
 

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Discussion Starter · #8 ·
Alright well I'm not sure what I'm looking for when checking the wastegate without the car running, I'm able to open/close it, seems smooth enough. I ziptied all my vaclines and checked for breaks/cracks visually they seem good, but my attempt at making a boost leak tester somewhat failed as my shitty air pump doesnt flow worth crap after 10 minutes it didnt even register 1psi.

I'll have to find someone with a decent compressor. In the meantime, I checked all the clamps and visually inspected, once again appears fine, the clamps are all tight and I dont want to go anymore as I broke a couple already putting this all together. I'll post my results after finding a compressor.

I made a video of like 2000-6500rpm in second at wot, theres no sound but I'm hoping this will confirm whether or not I'm right in that the car is slow. It shows speed&rpm, the second half of the video shows my boost guage when repeating the same run. I couldnt get all 3 into 1 image sorry and its somewhat shitty quality....The boost guage goes to 9 psi at the end.

 

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Discussion Starter · #9 ·
Alright so I used my compressor at work, charged pipes to 15psi and there are boost leaks, lol you guys were right.

The first leak was weird, I have one of the vacum lines from the intake mani going to the rear left of the valvecover with a pcv valve, and the valve musthave blown up because air was shooting right through and out the breather on the right. Before fixing this one the pressure dropped to 0 pretty fast.

Next I repressurized it and it leaked quickly but only until 10 psi then the leak slowed down. Anyway I used fantastic spray around the fuel injectors/intake mani and thats where the other leaks coming from. Surprisingly all the vacum lines were good, no rips or anything.

The far right and far left injectors leaked the most and for what I coul see only a tiny bit by the manifold, maybe I didnt tighten it enough, anyway I'm assuming the injector seals need replacing the ones I put on were somewhat old.

I disabled the mbc and boost now hits 6-7psi instead of 5, so hopefully it will goto 9 or whatever stock is when I'm done.

Sorry for the crazy long post but maybe this will help others.
I'm a little confused over the pvc setup, I thought that the right of the valve cover is connected by a straight hose/tube to between the turbo/airfilter(nonpressure), then on the top left theres a pcv valve that goes direct to the intake mani vacume port, if I am correct is there a stronger valve that can handle the boost?
 

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Discussion Starter · #10 ·
Alright so I crapped my pants today, I fixed the #4 injector seal leak and that on top of the previous pcv leave made a huge difference, but the other leaks are still substantial.

We should really make both a common leak when turboing section and a easy to read/understand pcv/vacum diagrahm.

I have 2 main questions left, first the injector seal I got was a lot different than the stock one, I'm talking about the one that goes on the pintle cap. The stock one is a thick round plastic ring with rubber on the inner diameter and 1 of the sides. The replacement I got was made completely of rubber, so you can actually sqish it if you want, and the external diameter was the same as the stock one but the internal wasnt, it fit very loosely on the pintle cap. It would actually fall off if you held it right side up so it was a little difficult getting the injector back in.

I am pretty confident its holding because there was a huge difference in power after changing it, but how well do you think it will hold up?

My second question relates to the pcv system, I have a picture that shows where things should go, but I've drawn a more simple picture of what I think it shows, please let me know if I'm correct...





As I understand, when theres negative pressure(vacum) the gases are sucked into the intake manifold to be burned, the pcv is there as a check valve function. When theres positive pressure(boost), there is a vacum created from the suction of the turbo drawing the gases through the right of the valve cover into between the turbo&vaf(coldpipe). The fact that theres shitty oil coming with the gas is why some put a catch can on the right hand side.

Does this sound correct?
 

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Discussion Starter · #11 ·
ok, well noone wanted to answer the first 2 questions lol, but I've got a new one. I bought new injector seals and they still leaked, I'm thinking maybe the rail is bent, I dont know why I'm the only one with this problem. Anyways off to home depot I went and found 1/2inch rubber grommets that were the same diameter but a little thicker, threw them on and pressureized intake, no more "injector" leaks!

So theres 2 more for sure, theres one on the passengers side of the intake manifold, so I got a new gasket, will change soon, and theres another big one under the throttle body that I cant find but I'll deal with it later.

Heres my question... I have the valve cover completely isolated, like the vacumm line for the pcv on the intake mani is plugged and the pcv valve is just sitting in the vc. On the right hand side I have a breather.

When I pressurize the system, air comes out of my valve cover???, does this make sense? The car is off obvisously and theres like 20 psi in all the piping, and theres no hose/line even going to the valve cover, I can put my finger over the holes and feel the air coming out.

Could this be valve seals or something?
 

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Discussion Starter · #13 ·
lol hopefully someone sees this so that I dont have to make a new thread.... I fixed my pcv system today,

on the right of the valve cover ran a line with an inline pcv valve to the pipe between air filter and turbo, so when im in boost the vacum created by the turbo will suck pcv in.

At the back of the valvecover, ran a line from the stock pcvvalve to a check valve, then to the intake mani so when at idle/nonboost the vacum will suck pcv in.

I'm pretty sure this is correct, but at idle if I remove the pcv valve, theres a shitload of air coming out of the valve cover, i know the crankcase can make pressure but its enough to try to push my finger off the hole.
 

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Discussion Starter · #15 ·
yea i've heard that pcv valves used to actually be check valves, in in the case of tturbos probably still are, but now I think they just stop the bulk of the oil and allow mostly vapours through, yet will allow air through in both directions. In either case I'm confident the check valve I added will not only hold 10psi, but also last a while as I left the stock pcv in it place.

My main concern before storing the car for winter is finding out why so much air is shooting out the valve cover, I know theres supposed to be a bit of pressure built up when your actually driving, but at idle it seems excessive. The feeling of the air is in pulses as if its leaking out the cylinders or something, i have no idea lol. If I can find my pressure testing equipment ill perform a test but I'm just looking for theoretical answers at this point.
 

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If you have your stock exhaust still on there, and have tracked down your boost leaks, rip the exhaust off and report back.

There is no way any turbo car is going to hit stock boost on the stock 1.5" piping or whatever crap it is. That could ABSOLUTELY cause your lower-than-stock boost.

(Ciento44)
 

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Discussion Starter · #17 ·
Well a year later I finally got around to fixing my exhaust. I bought a welder so I could do it myself. I'm running 2.5" turbo to the end, 2.5" highflow cat, and 2.5" borla muffler. Its very loud, I'll probably have to put a resonator in, but it sounds insane, no rice sound, its very deep and throaty.

Anyway this solved my problem, the car pulls like crazy now, seems like a lost a lot of low end but 3-7rpm is crazy.

I wonder if maybe i went a little overboard and adding a resonator give a bit more low end back...
 
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